The present invention relates to a cascode switching structure and, more particularly to using a low voltage P-channel MOSFET whose source is connected to a capacitor and its drain to a drain of a driver switch.
A cascode circuit is a technique for improving a performance of an analog circuit. It provides a very useful two-transistor configuration formed of a common source stage followed by a common gate stage. The cascode combines the two amplifier stages for increased output resistance and reduced parasitic capacitance, resulting in a high gain with increased bandwidth. The cascode provides better high-frequency performance and higher output resistance.
The cascoded configuration of a normally ON depletion mode and a normally OFF semiconductor devices allows reliable and safe operation in switching mode power supply systems.
Simple coupling of those two parts rely upon their own parameters for dynamic behavior, especially during a switch-OFF. The proposed arrangement enhances the switch-OFF transient, making use of the charge stored in VCC supply capacitor.